In later merger stages, after the first pericenter passage of the sub- and main halo, internal gas sloshing or tidal (also known as `slingshot') tails [1]}, [2]} can instead be recognized as arc-shaped high metallicity `fronts'. Internal gas sloshing is likely responsible for the high abundance arc in HCG 62 [3]}, [4]}, [5]}, [6]} and for the abundance map asymmetry in NGC5044 [7]}; although no 2D metal abundance map is available, radial profiles of an azimuthally resolved wedge in the NGC 7618 – UGC 12491 pair [8]} suggest a metal enhancement that was originally attributed to ram-pressure stripping but later recognized as rather due to a slingshot tail [2]}.
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